What Does Useful Mean?
The patent law specifies that inventions must be useful, which means have a useful purpose. Being useful also includes operativeness, meaning that an invention must operate or perform its intended purpose.The Average Cost to Patent an Invention
No entity that works professionally with the patent process publishes any average of the cost involved in patenting an invention. The U.S. Patent and Trademark Office simply publishes a list of the office fees, while the magazine IP publishes some ballpark numbers qualified with pages of discussion and the law firm Oppedahl Patent Law throws out a few numbers. state that an invention's complexity greatly determines the cost of the patent process.The Do-It-Yourself Patent Search
If you decide to do the patent search yourself, you have several search methods available: The USPTO (United States Patent Trade Office) Public Search Facility. The USPTO operates a Patent Public Search Facility located in Alexandria, Virginia. Here every U.S. patent granted since 1790 may be searched and examined. Many inventors like to make at least one pilgrimage to the Patent Public Search Facility. It's located fewer than 15 minutes from National Airport by taxi; Metro Rail serves it off the Blue and Yellow lines, King Street Station; and several hotels are within walking distance, so it's easy to get to and around.Direct-Hire Professional Search
If you want to save lawyer fees and mark-ups, consider going directly to a patent search firm. Searchers are best found through inventor grapevines, inventor associations, or university intellectual property departments. In larger cities, you can also check the Yellow Pages under "patent searchers." But be careful not to fall into a trap set by some disreputable invention marketing organizations. They list themselves in the phone book under "patent searchers" with a toll-free number. This is another way they hook unsuspecting inventors into service contracts. Get all the facts up front. Some reputable searchers ask for money up front if they don't know you. This is understandable. Just be sure you get the cost of the search beforehand, and get—and check—references. The cost to search a utility patent in the Washington, D.C., area runs between $500 and $1,000. It is roughly $100 per hour for a competent search. Once the search has been completed, if you want to obtain an opinion on the patentability of your invention, add the cost of your lawyer. If you need to show a prospective licensee that your invention has a good shot at a patent or that it's unlikely to infringe on an existing product, a letter from competent patent counsel may do the trick.The Patent Classification System
Patents are organized by class and subclass of invention , similar to the way books are organized in a library). By using the classification system , you can find and examine patents that are in the same field (class) as your idea. The tutorial How to Conduct a Patent Search will introduce you to this form of searching, however, this is difficult material to master.